Refractory heater plate



156mg@ l Nov 17' 1925' c. w. WILLIAMS REFRACTORY HETER PLATE Filed Jan. 30, 1924 Yao f5 sa Patented Nov. 17, 1925.

UNITED STATES CLARENCE W. WILLIAMS, OF EAST PALESTINE, OHIO.

REFBACTORY HEATER PLATE.

Application tiled January 30, 1924. Serial No. 689,467.

To all ,whom it may4 concern.'

Be it known that I, CLARENCE W. W1L- LIAMs, a citizen of the United States, residing at East Palestine, in the county of Columbiana and State of Ohio, have invented certain new and useful Im rovemeirts in Refractory Heater Plates, o which the' following is a specification.

My invention relates to electric heating devices and particularly to refractory resistor-supporting means.

One object of my invention is to provide a refractory heater plate embodying means for permitting of easily and quickly inserting' a resistor member in and removing it from operative engagement therewith.

Another object of m invention is to provide a heater plate o refractory material embodying means for permitting of inserting a resistor member into a groove in one face thereof' b a movement of the resistor at substantiall)17 right angles to the surface of the plate.

In racticing my invention. I provide a flat p ate of refractory material having an open groove in one face thereof. A plurality of spaced lugs, integral with the inner wall of the groove, partially overhang it,l the clearance between the outer end of the respective lugs and the opposite wall ofthe groove being sufficient to permit of passino y therebetween a resistor member to be locate in the oove. A plurality of pairs of spaced ribs, integral with the op osite wall of the groove, serve to hold t e resistor member under the respective lugs.

In the single sheet of drawings,

Figure 1 is a to plan view of a heating unit comprising t e device embodying my invention Fig. 2 1s a view in section therethrough, taken on the line, I-II of Fig. 1, and

Fig. 3 is a fragmentary top plan view of a modified form of heating unit embodying my invention.

A refractory plate, designated b the numeral 11,' is shown as of substantia ly circular form and has, in one face thereof, a spiral groove 12 that is substantially open and is wider at the top thereof than at the bottom. The groove 12 has, at its outer end, a lat- .erally-extendin opening y13 through which a` suitable mac ine screw (not illustrated) may extend to constitute a terminal member for one end of a resistor. A similar opening 14 is provided at substantially the center of the plate 11, through which a suitable machine screw (not illustrated) may extend to constitute a terminal member for the other end of a resistor. e

A resistor member l5, o eratively associated with the'plat-e 11 an adapted to be located in the groove l2, comprises a suitable metallic resistor wire that is wound to substantially helical form. The outer end of the resistor extends through a small opening 16 located closely adjacent to the opening 13, and is suitably secured to the under or depending end of the hereinbefore mentioned terminalA member. A similar opening 17 is provided closely adjacent to the central opening 14, and the other end of the resistor member extends therethrough and is connected to the lower end of a terminal bolt that is located in and extends through the openin 14.

A purality of spaced lugs 18, integral with the inner side wall of the groove 12, are provided and extend substantially parallel to the face of the plate 11 and partially overhang the open groove 12.v The distance between the outer end of the respective'lugs 18 and the opposing surface of the outer wall of the groove is just sufficient to permit of moving the helically-wound resistor member 15 therebetween when the resistor member is to be inserted in, or removed from, its proper operative position in the groove 12. I have not deemed it necessary to designate each of the overhanging lugs illustrated in Fig. 1 of the drawings with a number, for the reason that their construction is identical and any desired number thereof may be employed and they may be spaced as may be thought necessary.

The rectangular openings 19 illustrated as located below each of the overhanging lugs are made b which exten through the body of the gran ular material comprising the refractory plate in order to properly form the overhan ing lugs hereinbefore described.V

eans for holding spaced portions of the helically-wound reslstor member 15 under the respective lugs 18 comprise pairs of spaced ribs 21 and 22 integral with the outer side wall of the groove and extendinfr at substantially right angles to the face of the plate 11. These ribs are located one on each side of the adjacent overhanging lugs and d0 rods provided in the mold,

not extend to the top surface of the plate. The overhanging lugs are also depressed be-V low the top surface of the plate in order that they may not be injured and broken off 1n case a relatively heavy cooking utensil is placed upon the plate l1.

In Fig. 3 of the drawings I have illustrated the overhanging lugs and the pairs of spaced ribs as ap lied to a refractory heater plate of substantially rectangular form and having substantially straight open grooves. A plate 23, of refractory material, is provided with a plurality of substantially parallel-extending open grooves 24, 25, 26, and

27, of substantially the same shape as the groove 12, it being understood that these grooves as shown constitute a part only of the total number. The grooves are so located and connected that a helically-wound resistor member28 may be located therein and extend from one to the other over substantially the entire surface of the plate.

A plurality of lugs 29, spaced at suitable intervals, integral with the inner surface of the side wall of the respective grooves and extending substantially parallel to the face of the plate are' provided and overhang the grooves. The space between the outer end of the lugs 29 and the opposing surface of the other side wall is just sullicient to permit of moving the resistor member 28 therebetween when the same is being placed in, or removed from its proper operative position in the respective grooves. A plurality of airs of spaced lugs 30 and 31, integral wit the opposing surface of the outer wall of the groove and extending substantially at right angles to the face of the plate, are located one on each side of the respective lugsv 29. Openings 32, located respectively underneath the overhanging lugs 29 are caused .by rods provided in the dies of the mold forming the plate 23 and particularly the overhanging lugs 29.

One end of the resistor member 28 may be connected to a terminal member consti` tuted by a suitable machine screw terminal v(not shown) that is located in and extends through an opening 33 located adjacent to one edge of the late 23.

When it is desired to insert the resistor member 15 into the groove 12 of the substantially circular plate 1l, the straightened end of the resistor member 15 may be pushed through the opening 16, after which the resistor member may be laid over the groove and pushed into the same by temporarily changing its shape relatively to the groove in onedirection unt-il it has been4 moved past the overhan inglugs 18. In order to move the helically-wound resistor member further downwardly until it is resting upon the bottom surface of the groove, it is neces` sary to locally bend the resistor to permit it to pass by the pairs of spaced ribs 2l and 22, that is, its shape is changed in the other direction relatively to said groove. I have illustrated this final deformed position of the resistor member in Fig. 1 of the drawing, where it is shown somewhat exaggerated yin order to bring out the action more clearly.

It is, of course, obvious that the helicallywound resistor member is resilient to a certain degree, this resiliency depending upon the size of wire employed and upon the diameter of the turns of the helix. It is, therefore, easy to bend the helically-wound resistor member slightly at spaced points in order to permit of first moving it past the lugs and then pastthe opposing ribs until it is resting in the bottom of the groove.

It is further evident that the overhanging lugs may be made longer if' the upper portion of the'groove is made wider, or if the outer diameter of the turns of the resistor member is made smaller.

Substantially the same method may be employed to place the resistor member 2S iu the grooves of the rectangular plate 23 illustrated in Fig. 3 of the drawing, and I have notillustrated the resistor member as being deformed, although this will happen if the resistor is very resilient and if the ribs 30 and 31 are relatively thick.

If it is necessary to remove the resistor member substantially the reverse process may be employed to that hereiubefore de scribed for placing the resistor member in the groove.

I am aware that a number of different means have been provided to hold a heli cally-wound resistor member in a groove provided in one face of such a refractory plate. One means comprises a plurality ot' spaced bridges extending from one wall of construction it is necessary that a greater lOO portion of the length of the resistor meml ber be threaded through under these bridges, a proceeding which requires a relatively large amount of time, is relatively expensive, and' therefore increases the cost of the complete heating unit. Another method is to provide a plurality of zigzag grooves having overhanging salient corners, the helieally-wound resistor member being initially pulled underthese overhanging corners while beingplaced in the grooves. As such va resistor member may become red hot in actual operation, it may expand sufficiently to permit portions thereof to move out from under the overhanging corners.

The device embodyingI my invention provides relatively simple means for holding a resistor member in a substantially open groove, which means permit of moving the resistor member into its proper operative position in the groove by a movement substantially at right angles to the face of the plate. The integral ribs located opposite sistor member will remain under the overhanging lugs no matter what temperature it may reach, and irrespective of Whether it loses its original resiliency.

While I have illustrated a particular number of overhanging lugs, I do not Wish to be limited thereto as any desired number may be employed and they may be located in regularly or in irregularly spaced positions relatively to each other.

Various modifications may be made in the device embodying my invention Without departing from the spirit and scope thereof, and all such modifications are intended to be covered by the appended claims.

I claim as my invention 1. A refractory heater plate having a groove in one face thereof for receiving a resistor member, and comprising an integral lug partially overhangingthe groove, and means opposite to said lug for holding a resistor membervunder the lug.

2. A refractory heater plate having a groove in one face thereof for receiving a resistor member, and embodying means for -retaining the resistor member in said ygroove, said means vpermitting the 4free movement of said resistor into said groove in a direction substantially at right angles plate, and embodying to the face'of said other means for hold1ng the resistor member in its proper operative position in said groove.

3. A refractory heater plate having a groove in one face thereof for receiving a resistor member, and comprising a lug integral with one of the side Walls of said groove and partially overhanging the same, and a Vrib integral with the other side Wall of said groove for holding the resistor member underV said lug.

4. A refractory heater plate having a groove in one face thereof for receiving a resistor member, and comprising a lug integral with one of the side Walls of said groove and partially overhanging the same,

and a pair of spaced ribs, located one on each side of and opposite to said lug, integral with the other side wall of said groove for holding the resistor member under said lug.

5. In a refractory heater plate, the combination with an open groove located in one face thereof, and a resilient resistor member located in said groove, of a resistorretaining lug integral with one of the side `Walls of said groove and extending substantially radially outwardly therefrom, the distance between the end of said lug and the opposing surface of the other wall of said groove ing sufficient to permit the resistor memberto be laced in the groove by a movement in a right angles to the surface of said plate,

irection substantially at and means located in said groove and integral With the other Wall thereof for holding the resistor member under the lug.

6. In a refractory heaterplate, the combination with an open groove located in one f 4tively to said groove and moving it. in a direction substantially -at right angles to the surfaceof said plate, said means serving to hold said resistor member in the groove after being placed therein.

' 7. A refractory heater plate having an i open groove in one face thereof for receiving a resistor member, and comprising a plurality of spaced lugs partially overhanging the groove andintegral with one of theside Walls thereof, and spaced pairs of ribs located one on each side of said lugs and integral With the other side Wall of said groove for holding spaced portions of a resistor member under the respective lugs in said groove.

8. A'refractory heater plate having an open groove in one face thereof for receiving a resistor member, and comprising a plurality of spaced, integral, resistor-retaining lugs extending substantially parallel to the face of the plate, and a plurality of spaced, integral, resistor-positioning ribs extending substantially at right angles to the face of said plate.

9. A refractory `heater plate having an open groove in one face thereof for receivby a movement substantially at right angles to the surface of said plate, and means for ositioning said resistor under said retainlng means, said positioning means causing said resistor member to be deformed relatively'to said groove.

11. In a refractory heater plate having va, Substantially open groove in one face thereof for receivlng a resiliently-Wound re- .sister member, and comprising a lurality of integral lugs extendlng parta y over said groove in a direction substantially-parallel to the face of said plate and permitting the insertion of said resistor into 4said roove by temporarily changing its shape 1n one direction relatively to said groove and moving it in a direction substantially at right angles to the surface of said plate, and resistor-positioning means causing a change of shape of said resistor inthe other direction relatively to said groove and holding spaced portions of the resistor member under said lugs.

12. A refractory heater plate having an open groove in oneface thereof for receiving a substantially resilientresistor member placeable in said groove by a movement 4thereof in a direction substantially at right angles to the surface of the plate, and comprising a plurality of spaced resistorretaining means partially overhanging said groove, and a plurality of resistor-positioning means for holding spaced portions of said resistor, under the resistor-retaining 20 means, said resistor-positionin means causing said resitor to he deforme relatively to said groove` y In testimony whereof I affix my signature.

,LARENCE W. VILLIAMS. 

